# SSH configuration file.
#
# Some options are set even if they are default to prevent /etc/ssh/ssh_config
# from overwriting them.

# Copyright (C) 2011-2013  Simon Ruderich
#
# This file is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This file is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this file.  If not, see <http://www.gnu.org/licenses/>.

# Undocumented (and not very well tested) feature. This drops the connection
# after 5 seconds of inactivity. Thanks to shad0VV in #openssh on Freenode
# (2012-11-04 18:40 CET) for telling me about this undocumented feature.
#
#     ServerAliveCountMax 0
#     ServerAliveInterval 5


# Rules for all hosts.
Host *

# Force protocol version 2 which is more secure (default).
    Protocol 2

# Disable X11 and agent forwarding for security reasons (defaults).
    ForwardX11 no
    ForwardAgent no
# Don't trust remote X11 clients. If enabled allows bad admins complete access
# to local X11!
    ForwardX11Trusted no

# Disable authentication methods I don't use.
    ChallengeResponseAuthentication no
    GSSAPIAuthentication no
    HostbasedAuthentication no
    KbdInteractiveAuthentication no
# Only enable those I need.
    PasswordAuthentication yes
    PubkeyAuthentication yes

# Use only authentication identity files configured in ~/.ssh/config even if
# ssh-agent offers more identities.
    IdentitiesOnly yes

# Bind local forwardings to loopback only. This way no remote hosts can access
# them (default).
    GatewayPorts no
# Abort if not all requested port forwardings can be set up.
    ExitOnForwardFailure yes

# Allow using -M (ControlMaster) to create a master SSH session which
# "tunnels" other connections to the same host, thus reducing the number of
# authentications (which are relatively slow) and TCP connections. The master
# sockets are stored in ~/.ssh (by default ControlPath is not set).
    ControlPath ~/.ssh/master-%l-%h-%p-%r
# Automatically create a new master session if there's none yet or use an
# existing one. This way the user doesn't have to use -M to enable a master
# manually. Don't set this option to "yes" or all SSH commands try to become
# the master session which is obviously not possible.
    ControlMaster auto

# Hash hosts in ~/.ssh/known_hosts to try to conceal the known hosts. Doesn't
# help if the ssh hosts are stored in the shell's history file or in this file
# as shortcut.
    HashKnownHosts yes

# Don't permit running local commands (default).
    PermitLocalCommand no

# Don't send any environment variables (default).
    SendEnv

# Check host IP in known_hosts when connecting to detect DNS spoofing
# (default).
    CheckHostIP yes
# Ask before adding any host keys to ~/.ssh/known_hosts (default).
    StrictHostKeyChecking ask